363kV Dead-tank CB,363kV CB

1, Superior interrupting capability These breakers can cope with all known switching phenomena (including line charging current, small inductive current etc). The severe rate of rise of the recovery voltage by a short-line fault and the high recovery voltage peak by out-of phase interruption are both cleaned by the efficiently designed interrupter. In magnetizing current switching, the over voltage is less than twice the applied voltage. No restrike or reignition occurs on charging current switching. They also have an advantage of long electrical endurance. 2, Reliable insulating and current-carrying capability Because of SF6 gas as the insulating medium in produces and even distribution of electrical field, the breaker have a reliable insulating capability. SF6 gas protects the contacts from oxidization and other chemical reactions as SF6 gas is stable and inert when used with most materials. Item 363kV CB single break 363kV CB double breaks 550kV CB double break 550kV CB single break Unit Installation Indoor or outdoor Ambient air temperature -30 40 °C Max. daily difference in temperature 25 °C Altitude ≤1000 (3000 for dead tank CB) m Relative humidity per month ≤90 % Earthquake intensity Horizontal acceleration 0.2 (0.4) g Vertical acceleration 0.1 (0.2 ) g Degree of Contamination III Max. Ice coating thinkness 10 mm Max. wind 35 m/s Rated voltage 363 550 kV Rated frequency 50 (60) 50 Hz Rated nominal current 3150 4000 4000 A Rated breaking current 50 50,63 50 kA Making current 125 125,160 125 kA Rated short-time withstand current 3s 50 50,63 50 kA Rated peak withstand current 125 125,160 125 kA Short-line fault breaking current leX90%, leX 75% kA Out-of-phase breaking current leX25%, kA Creepage distance 2.5, 3.1 cm/kv Rated 1 min power frequency withstand voltage Across breaks 720 657 890 998 kV To earth 510 510 740 680 kV Rated lightning impulse withstand voltage (peak) Across breaks 1175+295 1175+295 1675+450 1675+450 kV To earth 1175 1175 1675 1675 kV Rated switching impulse withstand voltage Across breaks 950+295 950+295 1175+450 1175+450 kV To earth 950 950 1175 1175 kV Rated 5 min. power frequency withstand voltage under zero-gage pressure Across breaks 1.3×363/√3 1.3×550/√3 kA To earth 1.3×363/√3 1.3×550/√3 kA Rated operating sequence O-0.3s-CO-180s-CO Open time ≤30 ≤20 ≤22 ms Breaking time ≤50 ≤40 ms Closing time ≤ 100 ms Close-open time 35-60 ms Operating asynchronism Between poles Open ≤3 ms Close ≤4 ms Across breaks Open ≤2 ms Close ≤2 ms Mechnical endurance ≥ 5000 Times Number of breaks per pole 1 2 1 Mechanism Pneumatic or hydraulic